From: Ju-Zhe Zhong <juzhe.zh...@rivai.ai> his patch implement decrement IV for length approach in loop control.
Address comment from kewen that incorporate the implementation inside "vect_set_loop_controls_directly" instead of a standalone function. Address comment from Richard using MIN_EXPR to handle these 3 following cases 1. single rgroup. 2. multiple rgroup for SLP. 3. multiple rgroup for non-SLP (tested on vec_pack_trunc). Bootstraped && Regression on x86. Ok for trunk ? gcc/ChangeLog: * tree-vect-loop-manip.cc (vect_adjust_loop_lens): New function. (vect_set_loop_controls_directly): Add decrement IV support. (vect_set_loop_condition_partial_vectors): Ditto. * tree-vect-loop.cc (_loop_vec_info::_loop_vec_info): Add a new variable. (vect_get_loop_len): Add decrement IV support. * tree-vect-stmts.cc (vectorizable_store): Ditto. (vectorizable_load): Ditto. * tree-vectorizer.h (LOOP_VINFO_USING_DECREMENTING_IV_P): New macro. (vect_get_loop_len): Add decrement IV support. --- gcc/tree-vect-loop-manip.cc | 177 +++++++++++++++++++++++++++++++++++- gcc/tree-vect-loop.cc | 37 +++++++- gcc/tree-vect-stmts.cc | 9 +- gcc/tree-vectorizer.h | 13 ++- 4 files changed, 223 insertions(+), 13 deletions(-) diff --git a/gcc/tree-vect-loop-manip.cc b/gcc/tree-vect-loop-manip.cc index ff6159e08d5..aae2e122b1a 100644 --- a/gcc/tree-vect-loop-manip.cc +++ b/gcc/tree-vect-loop-manip.cc @@ -385,6 +385,58 @@ vect_maybe_permute_loop_masks (gimple_seq *seq, rgroup_controls *dest_rgm, return false; } +/* Try to use adjust loop lens for non-SLP multiple-rgroups. + + _36 = MIN_EXPR <ivtmp_34, VF>; + + First length (MIN (X, VF/N)): + loop_len_15 = MIN_EXPR <_36, VF/N>; + + Second length: + tmp = _36 - loop_len_15; + loop_len_16 = MIN (tmp, VF/N); + + Third length: + tmp2 = tmp - loop_len_16; + loop_len_17 = MIN (tmp2, VF/N); + + Forth length: + tmp3 = tmp2 - loop_len_17; + loop_len_18 = MIN (tmp3, VF/N); */ + +static void +vect_adjust_loop_lens (tree iv_type, gimple_seq *seq, rgroup_controls *dest_rgm, + rgroup_controls *src_rgm) +{ + tree ctrl_type = dest_rgm->type; + poly_uint64 nitems_per_ctrl + = TYPE_VECTOR_SUBPARTS (ctrl_type) * dest_rgm->factor; + + for (unsigned int i = 0; i < dest_rgm->controls.length (); ++i) + { + tree src = src_rgm->controls[i / dest_rgm->controls.length ()]; + tree dest = dest_rgm->controls[i]; + tree length_limit = build_int_cst (iv_type, nitems_per_ctrl); + gassign *stmt; + if (i == 0) + { + /* MIN (X, VF*I/N) capped to the range [0, VF/N]. */ + stmt = gimple_build_assign (dest, MIN_EXPR, src, length_limit); + gimple_seq_add_stmt (seq, stmt); + } + else + { + /* (MIN (remain, VF*I/N)) capped to the range [0, VF/N]. */ + tree temp = make_ssa_name (iv_type); + stmt = gimple_build_assign (temp, MINUS_EXPR, src, + dest_rgm->controls[i - 1]); + gimple_seq_add_stmt (seq, stmt); + stmt = gimple_build_assign (dest, MIN_EXPR, temp, length_limit); + gimple_seq_add_stmt (seq, stmt); + } + } +} + /* Helper for vect_set_loop_condition_partial_vectors. Generate definitions for all the rgroup controls in RGC and return a control that is nonzero when the loop needs to iterate. Add any new preheader statements to @@ -468,9 +520,10 @@ vect_set_loop_controls_directly (class loop *loop, loop_vec_info loop_vinfo, gimple_stmt_iterator incr_gsi; bool insert_after; standard_iv_increment_position (loop, &incr_gsi, &insert_after); - create_iv (build_int_cst (iv_type, 0), PLUS_EXPR, nitems_step, NULL_TREE, - loop, &incr_gsi, insert_after, &index_before_incr, - &index_after_incr); + if (!LOOP_VINFO_USING_DECREMENTING_IV_P (loop_vinfo)) + create_iv (build_int_cst (iv_type, 0), PLUS_EXPR, nitems_step, NULL_TREE, + loop, &incr_gsi, insert_after, &index_before_incr, + &index_after_incr); tree zero_index = build_int_cst (compare_type, 0); tree test_index, test_limit, first_limit; @@ -552,8 +605,13 @@ vect_set_loop_controls_directly (class loop *loop, loop_vec_info loop_vinfo, /* Convert the IV value to the comparison type (either a no-op or a demotion). */ gimple_seq test_seq = NULL; - test_index = gimple_convert (&test_seq, compare_type, test_index); - gsi_insert_seq_before (test_gsi, test_seq, GSI_SAME_STMT); + if (LOOP_VINFO_USING_DECREMENTING_IV_P (loop_vinfo)) + test_limit = gimple_convert (preheader_seq, iv_type, nitems_total); + else + { + test_index = gimple_convert (&test_seq, compare_type, test_index); + gsi_insert_seq_before (test_gsi, test_seq, GSI_SAME_STMT); + } /* Provide a definition of each control in the group. */ tree next_ctrl = NULL_TREE; @@ -587,6 +645,101 @@ vect_set_loop_controls_directly (class loop *loop, loop_vec_info loop_vinfo, bias_tree); } + if (LOOP_VINFO_USING_DECREMENTING_IV_P (loop_vinfo)) + { + /* Create decrement IV: + + Case 1 (single rgroup): + ... + _10 = (unsigned long) count_12(D); + ... + # ivtmp_9 = PHI <ivtmp_35(6), _10(5)> + _36 = MIN_EXPR <ivtmp_9, POLY_INT_CST [4, 4]>; + ... + vect__4.8_28 = .LEN_LOAD (_17, 32B, _36, 0); + ... + ivtmp_35 = ivtmp_9 - _36; + ... + if (ivtmp_35 != 0) + goto <bb 4>; [83.33%] + else + goto <bb 5>; [16.67%] + + Case 2 (SLP multiple rgroup): + ... + _38 = (unsigned long) n_12(D); + _39 = _38 * 2; + _40 = MAX_EXPR <_39, 16>; + _41 = _40 - 16; + ... + # ivtmp_42 = PHI <ivtmp_43(4), _41(3)> + # ivtmp_45 = PHI <ivtmp_46(4), _39(3)> + ... + _44 = MIN_EXPR <ivtmp_42, 32>; + _47 = MIN_EXPR <ivtmp_45, 32>; + ... + .LEN_STORE (_6, 8B, _47, ...); + ... + .LEN_STORE (_25, 8B, _44, ...); + _33 = _47 / 2; + ... + .LEN_STORE (_8, 16B, _33, ...); + _36 = _44 / 2; + ... + .LEN_STORE (_15, 16B, _36, ...); + ivtmp_46 = ivtmp_45 - _47; + ivtmp_43 = ivtmp_42 - _44; + ... + if (ivtmp_46 != 0) + goto <bb 4>; [83.33%] + else + goto <bb 5>; [16.67%] + + Case 3 (non-SLP multiple rgroup): + ... + _38 = (unsigned long) n_12(D); + ... + # ivtmp_38 = PHI <ivtmp_39(3), 100(2)> + ... + _40 = MIN_EXPR <ivtmp_38, POLY_INT_CST [8, 8]>; + loop_len_21 = MIN_EXPR <_40, POLY_INT_CST [2, 2]>; + _41 = _40 - loop_len_21; + loop_len_20 = MIN_EXPR <_41, POLY_INT_CST [2, 2]>; + _42 = _40 - loop_len_20; + loop_len_19 = MIN_EXPR <_42, POLY_INT_CST [2, 2]>; + _43 = _40 - loop_len_19; + loop_len_16 = MIN_EXPR <_43, POLY_INT_CST [2, 2]>; + ... + vect__4.8_15 = .LEN_LOAD (_6, 64B, loop_len_21, 0); + ... + vect__4.9_8 = .LEN_LOAD (_13, 64B, loop_len_20, 0); + ... + vect__4.10_28 = .LEN_LOAD (_46, 64B, loop_len_19, 0); + ... + vect__4.11_30 = .LEN_LOAD (_49, 64B, loop_len_16, 0); + vect__7.13_31 = VEC_PACK_TRUNC_EXPR <vect__4.8_15, vect__4.9_8>; + vect__7.13_32 = VEC_PACK_TRUNC_EXPR <vect__4.10_28, vect__4.11_30>; + vect__7.12_33 = VEC_PACK_TRUNC_EXPR <vect__7.13_31, vect__7.13_32>; + ... + .LEN_STORE (_14, 16B, _40, vect__7.12_33, 0); + ivtmp_39 = ivtmp_38 - _40; + ... + if (ivtmp_39 != 0) + goto <bb 3>; [92.31%] + else + goto <bb 4>; [7.69%] + */ + create_iv (this_test_limit, MINUS_EXPR, ctrl, NULL_TREE, loop, + &incr_gsi, insert_after, &index_before_incr, + &index_after_incr); + tree step = gimple_build (header_seq, MIN_EXPR, iv_type, + index_before_incr, nitems_step); + gassign *assign = gimple_build_assign (ctrl, step); + gimple_seq_add_stmt (header_seq, assign); + next_ctrl = index_after_incr; + continue; + } + /* Create the initial control. First include all items that are within the loop limit. */ tree init_ctrl = NULL_TREE; @@ -704,6 +857,7 @@ vect_set_loop_condition_partial_vectors (class loop *loop, bool use_masks_p = LOOP_VINFO_FULLY_MASKED_P (loop_vinfo); tree compare_type = LOOP_VINFO_RGROUP_COMPARE_TYPE (loop_vinfo); + tree iv_type = LOOP_VINFO_RGROUP_IV_TYPE (loop_vinfo); unsigned int compare_precision = TYPE_PRECISION (compare_type); tree orig_niters = niters; @@ -753,6 +907,19 @@ vect_set_loop_condition_partial_vectors (class loop *loop, continue; } + if (LOOP_VINFO_USING_DECREMENTING_IV_P (loop_vinfo) + && rgc->max_nscalars_per_iter == 1 + && rgc != &LOOP_VINFO_LENS (loop_vinfo)[0]) + { + rgroup_controls *sub_rgc + = &(*controls)[nmasks / rgc->controls.length () - 1]; + if (!sub_rgc->controls.is_empty ()) + { + vect_adjust_loop_lens (iv_type, &header_seq, rgc, sub_rgc); + continue; + } + } + /* See whether zero-based IV would ever generate all-false masks or zero length before wrapping around. */ bool might_wrap_p = vect_rgroup_iv_might_wrap_p (loop_vinfo, rgc); diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc index ed0166fedab..6f49bdee009 100644 --- a/gcc/tree-vect-loop.cc +++ b/gcc/tree-vect-loop.cc @@ -973,6 +973,7 @@ _loop_vec_info::_loop_vec_info (class loop *loop_in, vec_info_shared *shared) vectorizable (false), can_use_partial_vectors_p (param_vect_partial_vector_usage != 0), using_partial_vectors_p (false), + using_decrementing_iv_p (false), epil_using_partial_vectors_p (false), partial_load_store_bias (0), peeling_for_gaps (false), @@ -2725,6 +2726,16 @@ start_over: && !vect_verify_loop_lens (loop_vinfo)) LOOP_VINFO_CAN_USE_PARTIAL_VECTORS_P (loop_vinfo) = false; + /* If we're vectorizing an loop that uses length "controls" and + can iterate more than once, we apply decrementing IV approach + in loop control. */ + if (LOOP_VINFO_CAN_USE_PARTIAL_VECTORS_P (loop_vinfo) + && !LOOP_VINFO_LENS (loop_vinfo).is_empty () + && !(LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo) + && known_le (LOOP_VINFO_INT_NITERS (loop_vinfo), + LOOP_VINFO_VECT_FACTOR (loop_vinfo)))) + LOOP_VINFO_USING_DECREMENTING_IV_P (loop_vinfo) = true; + /* If we're vectorizing an epilogue loop, the vectorized loop either needs to be able to handle fewer than VF scalars, or needs to have a lower VF than the main loop. */ @@ -10364,12 +10375,14 @@ vect_record_loop_len (loop_vec_info loop_vinfo, vec_loop_lens *lens, rgroup that operates on NVECTORS vectors, where 0 <= INDEX < NVECTORS. */ tree -vect_get_loop_len (loop_vec_info loop_vinfo, vec_loop_lens *lens, - unsigned int nvectors, unsigned int index) +vect_get_loop_len (loop_vec_info loop_vinfo, gimple_stmt_iterator *gsi, + vec_loop_lens *lens, unsigned int nvectors, tree vectype, + unsigned int index) { rgroup_controls *rgl = &(*lens)[nvectors - 1]; bool use_bias_adjusted_len = LOOP_VINFO_PARTIAL_LOAD_STORE_BIAS (loop_vinfo) != 0; + tree iv_type = LOOP_VINFO_RGROUP_IV_TYPE (loop_vinfo); /* Populate the rgroup's len array, if this is the first time we've used it. */ @@ -10400,6 +10413,26 @@ vect_get_loop_len (loop_vec_info loop_vinfo, vec_loop_lens *lens, if (use_bias_adjusted_len) return rgl->bias_adjusted_ctrl; + else if (LOOP_VINFO_USING_DECREMENTING_IV_P (loop_vinfo)) + { + tree loop_len = rgl->controls[index]; + poly_int64 nunits1 = TYPE_VECTOR_SUBPARTS (rgl->type); + poly_int64 nunits2 = TYPE_VECTOR_SUBPARTS (vectype); + if (maybe_ne (nunits1, nunits2)) + { + /* A loop len for data type X can be reused for data type Y + if X has N times more elements than Y and if Y's elements + are N times bigger than X's. */ + gcc_assert (multiple_p (nunits1, nunits2)); + unsigned int factor = exact_div (nunits1, nunits2).to_constant (); + gimple_seq seq = NULL; + loop_len = gimple_build (&seq, RDIV_EXPR, iv_type, loop_len, + build_int_cst (iv_type, factor)); + if (seq) + gsi_insert_seq_before (gsi, seq, GSI_SAME_STMT); + } + return loop_len; + } else return rgl->controls[index]; } diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc index 7313191b0db..b5e4bc59355 100644 --- a/gcc/tree-vect-stmts.cc +++ b/gcc/tree-vect-stmts.cc @@ -8795,8 +8795,9 @@ vectorizable_store (vec_info *vinfo, else if (loop_lens) { tree final_len - = vect_get_loop_len (loop_vinfo, loop_lens, - vec_num * ncopies, vec_num * j + i); + = vect_get_loop_len (loop_vinfo, gsi, loop_lens, + vec_num * ncopies, vectype, + vec_num * j + i); tree ptr = build_int_cst (ref_type, align * BITS_PER_UNIT); machine_mode vmode = TYPE_MODE (vectype); opt_machine_mode new_ovmode @@ -10151,8 +10152,8 @@ vectorizable_load (vec_info *vinfo, else if (loop_lens && memory_access_type != VMAT_INVARIANT) { tree final_len - = vect_get_loop_len (loop_vinfo, loop_lens, - vec_num * ncopies, + = vect_get_loop_len (loop_vinfo, gsi, loop_lens, + vec_num * ncopies, vectype, vec_num * j + i); tree ptr = build_int_cst (ref_type, align * BITS_PER_UNIT); diff --git a/gcc/tree-vectorizer.h b/gcc/tree-vectorizer.h index 9cf2fb23fe3..8af3b35324e 100644 --- a/gcc/tree-vectorizer.h +++ b/gcc/tree-vectorizer.h @@ -818,6 +818,13 @@ public: the vector loop can handle fewer than VF scalars. */ bool using_partial_vectors_p; + /* True if we've decided to use a decrementing loop control IV that counts + scalars. This can be done for any loop that: + + (a) uses length "controls"; and + (b) can iterate more than once. */ + bool using_decrementing_iv_p; + /* True if we've decided to use partially-populated vectors for the epilogue of loop. */ bool epil_using_partial_vectors_p; @@ -890,6 +897,7 @@ public: #define LOOP_VINFO_VECTORIZABLE_P(L) (L)->vectorizable #define LOOP_VINFO_CAN_USE_PARTIAL_VECTORS_P(L) (L)->can_use_partial_vectors_p #define LOOP_VINFO_USING_PARTIAL_VECTORS_P(L) (L)->using_partial_vectors_p +#define LOOP_VINFO_USING_DECREMENTING_IV_P(L) (L)->using_decrementing_iv_p #define LOOP_VINFO_EPIL_USING_PARTIAL_VECTORS_P(L) \ (L)->epil_using_partial_vectors_p #define LOOP_VINFO_PARTIAL_LOAD_STORE_BIAS(L) (L)->partial_load_store_bias @@ -2293,8 +2301,9 @@ extern tree vect_get_loop_mask (gimple_stmt_iterator *, vec_loop_masks *, unsigned int, tree, unsigned int); extern void vect_record_loop_len (loop_vec_info, vec_loop_lens *, unsigned int, tree, unsigned int); -extern tree vect_get_loop_len (loop_vec_info, vec_loop_lens *, unsigned int, - unsigned int); +extern tree vect_get_loop_len (loop_vec_info, gimple_stmt_iterator *, + vec_loop_lens *, unsigned int, tree, + unsigned int); extern gimple_seq vect_gen_len (tree, tree, tree, tree); extern stmt_vec_info info_for_reduction (vec_info *, stmt_vec_info); extern bool reduction_fn_for_scalar_code (code_helper, internal_fn *); -- 2.36.3